Ryan Sheckler is getting ready to celebrate a big milestone -- six years of sobriety -- and he tells TMZ Sports things have gotten so much better for him since he swore off booze. The skateboarding legend gave us a life update while at LAX this week ... and he raved about the sober lifestyle. He said it's helped him in all areas -- including on his board. "I'm headed to Paris right now to go skate," he told us. "I thought I was done competing. And I'm skating better than ever right now."